Compatibility of SOCKETS(BS2000) V21.0 with earlier versions

SOCKETS(BS2000) V21.0 is compatible with SOCKETS(BS2000) V2.7, 2.6, V2.5, 2.4, 2.3, V2.2, V2.1 and V2.0, i.e. existing Socket user programs can be executed in version 21.0.

If a Socket user program was produced with the user library SYSLIB.SOCKETS.210 then it will not run on systems with subsystem version V2.7 or lower.